1. Field of the Invention
The present invention relates to a fluid conduit which includes a seal which has a bore sealing element and a face sealing element, and, more particularly, such a seal for use in an automotive transmission oil supply.
2. Description of Related Art
In an automatic transmission, pressurized fluid is supplied to various clutches and brakes to effect a shift to a desired transmission gear ratio. The pressurized fluid is routed from a valve through a manifold and various passageways to a particular clutch being applied. One such clutch comprises a clutch cylinder having an internal spline driveably engaged with a plurality of clutch plates. The clutch plates are interlaced with a plurality of clutch plates which are engaged to a hub through a splined engagement.
The oil passageway for such a clutch includes a radially directed bore through the wall of the transmission case in registration with a corresponding passageway in the clutch cylinder.
As illustrated in Prior Art FIG. 1, a tube 10 is provided to be inserted in the bore of a transmission case to provide a fluid passageway through the transmission case to the passage in the cylinder. Such a tube 10 includes a face seal 18 at an end 15 thereof to communicate fluid therethrough to the cylinder, while attempting to not lose fluid to the environment around the cylinder. The tube 10 comprises a hollow rigid substrate 11 with a slotted end 13 to provide an oil passageway.
The prior art tube 11 thus includes a lip seal 18 provided at an end 15 in abutment with the outer surface of the cylinder around the periphery of the passageway provided in the cylinder. The lip seal 18 also includes a circumferential rib 16 on the outer surface thereof which engages the bore in the transmission case to prevent fluid from escaping around the seal 18 from within the bore. The opposite end 13 of the rigid tube bears against a rigid transmission member such as a manifold or cover plate.
In a prior art transmission using such a seal, the lip seal 18 had to be of an axial length to accommodate any manufacturing and assembly tolerances in the tube, seal, transmission case, clutch cylinder, manifold, and any other related member within the transmission assembly. Thus, for example, if the outside diameter of the clutch cylinder varied, the lip seal must accommodate the associated radial variation. Likewise, any tolerance in the transmission case relative to the manifold would also be taken up by the length of the lip seal. Because of these tolerances, the lip seal has a length which exceeds that which would be desirable. This excessive length may cause a blowout or extrusion of the seal when the pressure of the fluid exerts a force on the seal which exceeds the rigidity of the seal. And if the seal were too short, fluid would leak. Further, such a long lip may be damaged during installation, because the bore in the case may have a sharp corner due to the manufacture thereof. In any such situation, the result is clutch slippage due to inadequate pressure because of fluid loss.
It would therefore be desirable to provide a seal which provides a fluid conduit and accommodates variation in the transmission assembly without comprising the integrity of the seal.